Take-up mechanisms for sewing machines



June 12, 1956 R. E. JOHNSON 2,749,863

TAKE-UP MECHANISMS FOR SEWING MACHINES Filed Nov. 13, 1953 sSheets-Sheet 1 INVENTOR.

Ralph E. Johnson WITNESS Maw/@ 97 BY W ATTORNEY June 12, 1956 R. E.JOHNSON TAKE-UP MECHANISMS FOR SEWING MACHINES 5 Sheets-Sheet 2 FiledNOV. 15, 1953 INVENTOR. Ralph E. Johnson WITNESS WMQWM AT TORNE Y June12, 1956 R. E. JOHNSON 2,749,863

TAKE-UP MECHANISMS FOR SEWING MACHINES Filed Nov. 13, 1953 5Sheets-Sheet 3 INVENTOR. Ralph E. Johnson WITNESS BY ATTORNEY June 1956R. E. JOHNSON TAKE-UP MECHANISMS FOR sswmc; MACHINES 5 Sheets-Sheet 4Filed Nov. 15, 1953 Fig.7.

INVENTOR. Ralph E. Johnson W/ TNESS Z/MWM ATTORNEY June 12, 1956 R. E.JOHNSON 2,

TAKE-UP MECHANISMS FOR SEWING MACHINES Filed Nov. 13, 1953 5Sheets-Sheet 5 INVENTOR. Ralph E. Johnson WITNESS BY M ATTORNEY UnitedStates Patent TAKE-UP MECHANISMS FOR SEWING MACHINES Ralph E. Johnson,Mountainside, N. 1., assignor to The Singer Manufacturing Company,Eiizabeth, N. 1., a corporation of N ew Jersey Application November 13,1953, Serial No. 392,003

' Claims. (Cl. 112248) This invention relates to thread-controllingmechanisms for sewing machines: and, more particularly, to rotaryneedle-thread take-ups for lock-stitch sewing machines.

In the formation of lock stitches by sewing machines, whether employinga movable hook or a shuttle, control of the needle-thread concatenationis accomplished primarily by the needle-thread take-up. It is desirablein these machines that the take-up draw in and pay out thread preciselyin accordance with the thread requirements of the stitch-forminginstrumentalities so that the needle-thread will be under proper controlat all times. The needle-thread requirements of both hooks and shuttlesare basically similar in that the needle-thread loop after beingenlarged and passed about the under thread mass, must be drawn up andset into the work fabric rapidly, usually in less than a third of thecycle of stitch formation. During the remaining two thirds or more ofthe stitching cycle the needle-thread must be paid out by the take-up invarying amounts. First, the take-up must provide slack thread toaccommodate penetration of the work by the needle, and then as theneedle begins to withdraw and in so doing throws out a loop for seizureby the hook or shuttle, this slackening process must be' retarded so asto maintain a precise control of the needlethread loop at the criticalpoint of loop seizure. Finally after loop seizure, the needle-threadmust be slackened rather quickly as the hook or shuttle spreads theneedlethread loop about the bobbin of under thread.

In the past, many varieties of take-up mechanisms have been utilizedwith varying degrees of success.

The so-called link take-up comprising an oscillatory or reciprocatorylinkage, including a thread-engaging lever-arm, has been developed tothe pointat which the thread requirements of the hook or shuttle may bematched very closely. When operated at-very high speeds link take-upsare inherently troublesome from the standpoint of excessive vibration.Moreover, the action .of link take-ups upon the thread is a harsh one,and they present a design and safety problem because of the exposedswinging take-up lever.

Rotary take-ups have been used to obviate one or more of thedifiiculties found in link take-ups. It is well recognized that a rotarytake-up will present less of a vibration problem and will act upon thethread in a smooth and gentle manner. However, the difficulty withrotary take-ups has been that of providing a precise control of thethread in accordance with the critical demands of a hook or shuttle. Forthis reason, successful rotary take-ups have in the past taken one oftwo forms, either they are disproportionately large and with a pluralityof thread-engaging parts, or they employ a plurality of separate smallrotating members.

From the standpoint of cost, vibration, and design, the most desirabletake-up would involve a single rotating thread-engaging member which issmall enough to be accommodated inconspicuously within a normal sewingmachine frame. Attempts along this line have been made 2,749,863Patented June 12, 1956 in the past, however, in most instances thesetake-ups operated to utilize only a fraction of the motion of thethread-engaging element in order to take-up the thread quickly and toset the stitch. The thread is then disengaged or released from thistake-up element and slackened out of control during a major portion ofthe remainder of the stitch-forming cycle. These prior takeups,therefore, serve only to set the stitch and fail to provide the precisecontrol of the needle-thread at the remaining critical points in thestitching cycle.

It is an object of this invention to provide a rotary take-up comprisinga single rotary thread-engaging member.

It is a further object to provide a single rotary takeup mechanismarranged to provide a continuous and positive control on the threadduring both the thread take-up and the thread slackening portions of thestitch-forming cycle.

A more specific object of this invention is to provide a rotary take-upmechanism having a single thread-engaging member arranged to travel in anon-circular path and at non-uniform velocity so as to provide athreadcontrolling action precisely in accordance with the threadrequirements of the stitch-forming instrumentalities.

With these and other objects and advantages in view, as will hereinafterappear, this invention comprises the devices, combinations andarrangements of parts hereinafter described and illustrated in theaccompanying drawings, in which:

Fig. 1 is a side elevational view, partly in section, of

' a sewing machine having the take-up of my invention applied thereto;

Fig. 2 is an end elevational view of a portion of the sewing machine ofFig. 1;

Fig. 3 represents a cross-section taken substantially along line 33 ofFig. 2;

Fig. 4 is a fragmentary end elevational view of the sewing head of thesewing machine of Fig. 1 with the end-cover plate removed;

. .Fig. 5 is an elevational view of the inside of the end cover-plate ofFigs. 1, 2 and 3;

Fig. 6 is a view of the take-up thread-engaging member of Fig. 2,together with a diagrammatic representation of the path of motion of thethread-engaging member and the velocity thereof at various criticalpositions during a cycle of operation;

Fig. 7 is an end elevational view of a sewing machine and including amodified form of my invention;

Fig. 8 represents a cross-section taken substantially along line 8-8 ofFig. 7;

Fig. 9 is a fragmentary end elevational view of the sewinghead of thesewing machine of Fig. 7 with the end cover-plate removed;

Fig. 10 is an elevational view of the inside of the end cover-plate ofFigs. 7 and 8; and

Fig. 11 is a view of the take-up thread-engaging member of Fig. 7together with a diagrammatic representation of the path of motion of thethread-engaging mem ber and the velocity thereof at various criticalpositions during a cycle of operation.

Referring more particularly to Fig. 1 of the drawings, the presentinvention is illustrated as applied to a lockstitch'sewing machineemploying a rotary hook. The sewing machine of Fig. 1 is provided with aframe including a bed 20 from which rises a standard 21 which supports abracket arm 22 terminating in a sewing head 23. Journaled in thebracket-arm is a main shaft 24 which is driven as by an electric motor25. The main shaft 24 is geared through a vertical shaft 26 to a bedshaft 27 which rotates at twice the speed of the main shaft. A rotaryhook 28 is secured directly to the outboard extremity of the bed shaft.

Referring to Fig. 3, the main shaft 24 is provided in the sewing head 23with a crank mechanism including a counterbalance 29 which provides aneedle-bar actuating crank. Carried in the counterbalance by means of aset screw St} is a needle-bar actuating crank pin 31 formed with a head32. A needle-bar driving link 33 is fitted at one end on the crank pinand at the other end embraces a pin as which is carried by a needle-bar35. The needle-bar is journaled for endwise reciprocatory motion in thesewing head and carries at its lower end a needle 36. Fastened to thehead 32 of the needle-bar actuating crank pin 31, as by screws 37, is anadditional crank member 38 formed with a take-up actuating crank pin 39.

Secured to the sewing head by screws 40 is an end coverplate 41 which isformed with a circular aperture 42 within which the take-up operates.The cover-plate is formed about the aperture 42 with an oval-shapedprotuberance 43 which is formed with a similarly oval-shaped counterbore44. The counterbore 44 is joined by a downwardly extending slot 45within which slot is seated a bridge piece 46 secured to the face plateby screws 47. The bridge piece is provided with an outward projection 48which is formed with an inwardly extending slot 49. Fast on the bridgepiece above the slot 49 and disposed within the counterbore 44 is anon-circular disk 50 which is disposed in a plane substantiallyperpendicular to the axis of the sewing machine main shaft 24. The disk50 is thus rigidly supported in a fixed position with respect to thesewing machine frame.

The moving parts of the take-up mechanism of this invention are carriedby the disk 50 and are adapted to be actuated by the take-up actuatingcrank-pin 39. To this end, crank-pin 39 is embraced by a bearing member51 in the form of an apertured lug which is carried at one extremity ofa cylindrical take-up member 52. A control member in the form of a blockor bushing 53 slidably embraces the take-up member, and the bushing is,in turn, pivotally secured to the inner surface of disk 50 by a pivotscrew 54. As indicated in Figs. 2 and 6, the pivot screw 54 is oifsetfrom the axis of the sewing machine main shaft, but the axis of thispivot screw is disposed within the path of rotation described by thetake-up actuating crank-pin 39. Secured at the free extremity of thecylindrical takeup member 52 in a thread-engaging finger 55 which isbent to extend about the periphery of the disk 50 and to projectoutwardly beyond this disk. It will be noted that the slot 49 in thebridge piece is formed sufliciently. large to accommodate the passage ofthe thread-engaging finger.

As shown clearly in the diagram of Fig. 6, the circular pathdescribed bythe take-up actuating crank pin 39 approaches and recedes from theoffset pivotal axis of the control member pivot 54. The resulting pathof motion of the threadrengaging finger 55, therefore, is in a non?circular path as shown in dashed lines in Fig. 6. The non.- circularshape of the disk 50, above referred to, is formed to coincidesubstantially with the shape of the path dew scribed by thethread-engaging finger 55.

Pivoted as at 56 to the projection 48 on the bridge piece 46 is an anglebracket 57 to which is secured, as by screws 58, a take-up guard plate59. The guard plate may be turned about pivot 56 to expose the disk 50and the thread-engaging finger 55, and is provided with a spring-biasedlatch pin 60 for the purpose of releasably maintaining the guard platein closed position. The inner surface of the guard plate is providedwith an oval slot 61 shaped in a manner corresponding to the peripheryof the disk 50 and adapted to accommodate the free ex, trernity of thethread-engaging finger 55.

When in closed position, as in Fig. 3, the guard plate is disposedgenerally parallel to the disk 50 and spaced slightly therefrom toprovide a needle-thread accommodating slot 62 which is open upwardly andbroken only by 4 the bridge piece 46 at the bottom. Both the disk 50 andthe slot 62 between disk 50 and the guard plate 57, therefore, aredisposed within the path of travel of the threadengaging finger 55.

The thread path through the take-up is best illustrated in Fig. 2. Froma suitable supply the thread is directed through guide wire 63downwardly about the usual tension device 64 and a check spring 65associated with the tension device. From the check spring the threadleads upwardly and through the slot 62 between the guard plate and thedisk 59. The thread is then directed over both the bridge piece and thethread-engaging finger 55. From the slot 62, the thread is leddownwardly through a wire guide 66 on the sewing head and a guide member67 on the needle-bar 35 to the eye of the needle.

it will be appreciated that not only the guides 63, 66 and 67, but alsothe tension device 64 and the above described rotary take-up areself-threading. By self-threading it is meant that the operator mayproperly thread each of these instrumentalities by a single movement ofone hand without releasing her grip upon the thread.

The operation of the rotary take-up of my invention can best beillustrated with reference to Figs. 2 and 6. Fig. 6 illustrates thethread-engaging member of Fig. 2, together with a diagrammaticillustration of the path of movement of the thread-engaging finger 55 aswell as the take-up actuating crank pin 39, and the relativeinstantaneous velocities at various critical points during a typicalstitching cycle. For this purpose, the instantaneous velocity of thecrank pin 39 has been assumed to be constant and of the magnitudeillustrated. The velocities of the threadengaging finger at the variouspoints are correspondingly proportionate to the length of the vectorsillustrated.

In Fig. 2 the sewing machine parts are illustrated at a point in thestitch-forming cycle shortly after seizure of the needle-thread loop bythe hook and as the needlethread loop is being expanded and carried bythe hook about the bobbin. The take-up in Figs. 2 and 3 rotates in aclockwise direction. As is indicated in Fig. 2, the bridge piecepartially supports the thread at this point, and as the thread-engagingfinger 55 passes through the slot 49 in the bridge piece, the thread ismomentarily supported entirely by the bridge piece and, thus, pre ventedfrom dropping out of the take-up mechanism. As the thread-engagingfinger emerges from the slot 49 and re-engages the thread, theneedle-thread loop will have been carried about the bobbin by the hookand the needlethread must be rapidly drawn up and the stitch set. InFig, 6;,point E corresponds to the point at which the threadeengagingfinger emerges from the slot in the bridge piece while point Bcorresponds to the point at which the stiteh is set. Point E to point Bin Fig. 6 thus represents the takeup portion of the cycle of take-upoperatiOn. It will be apparent that the velocity of the threadengagingfinger is far greater from point B to point B than during the remainderof the cycle. In addition, the path of motion of the finger 55 is notcircular but rather is somewhat oval-shaped, it being elongated in thedirection from E to B thus lengthening the path of motion during thetakerup action. On the path of motion of the crank pin 39 in Fig. 6, thepoints marked in lower case letters indicate the positions of the crankpin corresponding to each of the illustrated critical points of thethread-engaging finger 55. It will be apparent that due to the locationof the control member 53 and its pivotal axis 54, the movement of finger55 from E to B is accomplished in approximately of crank and main shaftrotation or approximately a fourth of the stitch-forming cycle.

PointC, in Fig. 6 represents the point at which the needle penetratesthe work. It will be noted that the velocity of the thread-engagingfinger 55 has been reduced considerably at this point so that the slackthread will be payed out in accord nce with the demands of the amasesdescending needle and without objectionable uncontrolled thread existingin the system.

Point D in Fig. 6 corresponds to the point of needleloop seizure by thehook. The velocity of the finger 55 at this point in the cycle is at aminimum so that the giving up of thread by the take-up is retarded atthis point. With this arrangement the take-up retains positive controlover the needle thread during loop seizure and the danger of excessivelooseness of thread is obviated at this critical point in the stitchingcycle.

As the parts continue to move from point D, the needle thread is pickedup by the hook and a loop is drawn down around the bobbin. The take-up,therefore, must give up the necessary amount of slack thread quicklyafter loop seizure. The diagram of Fig. 6 indicates that with thetake-up of my invention, the velocity of the take-up finger increasesvery quickly from point D to point B and thus matches perfectly theincreased thread demands of the hook.

It will be appreciated that an infinite variety of hook sizes may beutilized with the take-up of my invention and that differences in threadrequirements of various hooks may be satisfied not only by dimensionalchanges in the take-up member but also by a proper choice of theposition of the pivotal axis of the control member 53. In all cases, mytake-up mechanism positively controls the thread during the entirestitching cycle and provides proper amounts of thread at all times inprecise accordance with the requirements of the stitch-forminginstrumentalites.

Figs. 7-11 illustrate a modified form of the take-up of my invention,and in addition, show the take-up as applied to a lock-stitch machine ofthe type employing an oscillatory shuttle.

The sewing machine of Figs. 7-10 is provided with a frame styled similarto that of Fig. 1 and including a bed having a work-supporting plate 70,a vertical standard 71, and a bracket arm terminating in a sewing head72. As in the sewing machine of Fig. 1, a needle bar 73 car rying aneedle 74 is journaled for reciprocation in the sewing head 72. Theneedle-bar is actuated by means of a link 73 which embraces a needle-baractuating crank pin 75 which is fixed in a needle-bar actuating crankmechanism on a main shaft 76 journaled in the bracket arm. The machinediffers from that of Fig. l primarily in that an oscillatory shuttle 77is provided beneath the worksupporting plate 70 to cooperate with theneedle. The shuttle may be oscillated in one-to-one relation with therotation of the main shaft by suitable means known in the art.

The sewing head 72 is closed by means of an end coverplate 78 secured inplace by screws 79. The end coverplate is apertured as at 80 toaccommodate the take-up mechanism and is provided beneath the aperturewith a bridge piece 81 which is slotted as at 82 and is secured to theend cover-plate by locating pins 83 and a fastening screw 84. Secured tothe bridge piece by screws 85 is a disk 37 formed with an inturnedperiphered rim 88 which is somewhat heart-shaped and extends within theaperture 80 of the end cover-plate.

The rotary thread-engaging member of the take-up mechanism is carried bythe disk 87 and is adapted to be actuated from the needle-bar actuatingcrank mechanism on the main shaft in a manner similar to that of theabove described form of Figs. 1-6. The modified form, however, difiersin that the rotary take-up mechanism is provided by means of a lever 89formed at one end with a bearing 90 adapted to embrace a take-upactuating crank pin 91 carried by a crank 92 which is secured to theneedlebar actuating crank pin 75. Between its ends as at 94 the lever 89is pivoted to an anchor link 95 which, in turn, is pivoted to the disk87 as by screw 96 at a point within a projection of the path of motiondescribed by the take-up actuating crank pin 91. The free end of thetake-up lever is formed with a thread-engaging finger 97 bent to extendabout the peripheral rim 88 of the disk 87. The finger 97 is also formedwith a thread-controllink tail 98.

A guard-plate 99 is disposed adjacent disk 87 and is secured in place onthe bridge piece 81 by means of a bracket member 100 and screws 101. Theguard plate 99 is formed with a substantially circular outer edgeportion 102 and with a heart-shaped inner portion 103 which is shapedsubstantially similar to the disk 87. The inner portion 103 of the guardplate is disposed in spaced relation to the disk 87 to define a narrowthread-accommodating slot 104. Both the slot 104 and the disk 87 aredisposed completely within the path of motion described by thethread-engaging finger 97.

The thread path through the take-up extends from a supply through thewire guide 105 to the tension device 106, a check spring 107, then intothe slot 104 between the guard plate 99 and the disk 87 and to a wireguide 108 on the bridge piece to a thread-guiding slot 109 formed in thebottom edge of the end cover-plate, and then to the usual guide 110 onthe needle bar and to the needle.

Fig. 11 which illustrates the path of motion of the thread engagingfinger 97, indicates the velocity of the finger, at the same fivecritical points during the stitching cycle as are illustrated anddiscussed with reference to Fig. 6.

Briefly, from point E to point B the finger 97 is taking up theneedle-thread, stitch setting occurring near point B. As shown by thecorresponding positions of the takeup actuating crank pin 91, marked inlower case letters, the take-up action from E to B is accomplished inless than one-third of the stitching cycle, the velocity of the fingerbeing increased to a maximum during take-up.

The path of motion of the finger 97 is generally heartshaped being alsoelongated in the direction from E to B. C represents the point of needlepenetration. At point D, which coincides with needle-loop seizure by theshuttle, the velocity of the thread-engaging finger 97 is decreased to aminimum value. In addition, the path of motion of the finger 97 dipsinwardly at the point of loop seizure, which together with the decreasein velocity provides for a retardation of the thread slackening processand a corresponding factor of precise control over the needle thread.

Having thus set forth the nature of the invention, what I claim hereinis:

1. A rotary take-up mechanism for a sewing machine having a frame, ashaft journaled for rotation in said frame, and a crank mechanismincluding a crank-pin carried for rotation with said shaft, said take-upmechanism comprising a frame extension disposed axially opposite saidcrank mechanism, means rigidly securing said frame extension to saidsewing machine frame, a take-up member disposed between said frameextension and said crank mechanism, a bearing carried by said take-upmember having a frame, a shaft journaled for rotation in said.

frame, and a crank mechanism including a crank-pin carried for rotationwith said shaft, said take-up mechanism comprising, a frame extensionincluding a take-up supporting member disposed axially opposite saidcrank mechanism, a bridge-piece fixed to said take-up support ingmember, and means rigidly securing said bridge-piece to said sewingmachine frame, a take-up member disposed between said take-up supportingmember and said crank mechanism, a bearing carried by said take-upmember and journaled on said crank-pin, a control link operativelyconnected to said take-up member, means pivotally securing said controllink to said take-up supporting member on an axis disposed within thepath of motion described by said crank-pin, and a thread-engaging fingerprojecting from said take-up member, said thread-engaging finger beingdisposed to extend about the edge of said take-up supporting member.

3. In a lock-stitch sewing machine having a bracket arm, a rotary shaftjournaled in said bracket arm, a needlebar journaled for endwisereciprocatory motion in said bracket arm, a crank mechanism carried bysaid shaft, and needle-bar driving connections with said crankmechanism, a rotary take-up mechanism comprising a singlethread-engaging finger, means actuated by said crank mechanism forimparting motion to said thread-engaging finger in a non-circular path,a plate having a periphery shaped to coincide substantially with thenon-circular path of motion of said thread-engaging finger, and meansrigidly supporting said plate from said bracket arm in a positioncompletely within the path of motion of said thread-engaging finger.

4. In a lock-stitch sewing machine having a bracket arm, a rotary shaftjournaled in said bracket arm, a needle-bar journaled for endwisereciprocatory motion in said bracket-arm, crank mechanism carried bysaid shaft, and needle-bar driving connections with said crankmechanism, a rotary take-up mechanism comprising a plate rigidlysupported on said bracket-arm, said plate having an inner and an outerface, said inner face being disposed in axially spaced relation to saidcrank mechanism, a single thread-engaging finger extending about theedge of said plate, means carried adjacent the inner face of said plateand actuated by said crank mechanism for imparting motion to saidthread-engaging finger in a non-circular path, and means disposedadjacent the outer face of said plate for confining a loop of threadwithin the path of motion of said thread-engaging finger.

5. In a lock-stitch sewing machine having a bracket arm, a rotary shaftjournaled in said bracket arm, a needlebar journaled for endwisereciprocatory motion in said bracket-arm, a crank mechanism carried bysaid shaft, and needle-bar driving connections with said crankmechanism, a rotary take-up mechanism comprising a single threadengagingfinger, means actuated by said crank mechanism for imparting motion tosaid thread-engaging finger in a non-circular path, a plate having aperiphery shaped to coincide substantially with the non-circular path ofmotion of said thread-engaging finger, means rigidly supporting saidplate from said bracket arm in a position completely within the path ofmotion of said thread-engaging finger, and a guard member secured inspaced relation to said plate to define therebetween a slot adapted toconfine a thread loop within the path of motion of said threadengagingfinger.

6. In a sewing machine having a frame and a shaft journaled in saidframe, a thread take-up mechanism comprising, a support member carriedby said frame, means associated with said support member defining athread compartment at one side of said member, a take-up memberpivotally supported on said support member at the side thereof oppositesaid thread compartment, a finger carried by said take-up member andextending into said thread compartment, and means for actuating saidtake-up member comprising a crank member carried by said shaft, and anoperative connection between said crank member and said take-up member.

7. Ina sewing machine having a frame, a shaft journaled in said frame,and a crank mechanism including a take-up actuating crank-pin carried bysaid shaft, a rotary take-up mechanism comprising, a take-up member, athread-engaging finger carried by said take-up member, mechanismactuated by said crank mechanism for imparting motion in a non-circularpath to said threadengaging finger, said mechanism comprising a bearingcarried by said take-up member and journaled on said take-up actuatingcrank'pin, a control link operatively connected with said take-up memberbetween said bearing and said thread-engaging finger, a plate havingperiphery shaped to coincide substantially with the non-circular path ofmotion of said thread-engaging finger, means pivoting said control linkto said plate, and means securing said plate to said sewing machineframe in a position completely Within the path of motion of saidthreadengaging finger and with the pivotal axis of said anchor linkbeing disposed within the path of motion of said crank-pin.

8. In a sewing machine having a frame, a shaft journaled in said frame,and a crank mechanism including a take-up actuating crank-pin carried bysaid shaft, a rotary take-up mechanism comprising a plate rigidlysupported on said frame, said plate having an inner and an outer face,said inner face being disposed in axially spaced relation to said crankmechanism, a single thread-engaging finger extending about the edge ofsaid plate, means carried adjacent the inner face of said plate andactuated by said crank mechanism for imparting motion to saidthread-engaging finger in a non-circular path, said means comprising atake-up member, means securing said thread-engaging finger to saidtake-up member, a bearing carried by said take-up member and journaledon said crank-pin, a control link operatively connected to said take-upmember, and means pivotally securing said control link to said plate onan axis disposed within the path of motion described by said crank-pin,and a guard member disposed in spaced relation to the outer face of saidplate to define therebetween a slot adapted to confine a thread loopwithin the path of motion of said threadengaging finger.

9. In a sewing machine having a frame, a needle supported for endwisereciprocation in said frame, and mechanism in said frame operativelyconnected to reciprocate said needle, a rotary needle-thread take-upmechanism comprising in combination a rotary threadengaging finger,means driven by said needle actuating mechanism for imparting motion tosaid thread-engaging finger in a non-circular path, a pair ofsubstantially planar thread-guiding members, a bridge piece joining saidmembers and maintaining said members in spaced relation defining athread-accommodating slot therebetween, and means supporting saidthread-guiding members from said sewing machine frame with saidthread-accommodating slot and said bridge piece disposed within the pathof motion described by said thread-engaging finger.

10. A rotary take-up mechanism for a sewing machine having a frame, ashaft journaled for rotation in said frame, and a crank-pin carried forrotation with said shaft, said take-up mechanism comprising a frameextension disposed axially opposite said crank mechanism, means rigidlysecuring said frame extension to said frame, a cylindrical take-upmember, a bearing carried by said cylindrical member and journaled onsaid crank-pin, a slide-block disposed to embrace said cylindricalmember, means pivotally securing said slide block to said frameextension on an axis parallel to that of said crank mechanism anddisposed within the path of motion described by said crank-pin, athread-engaging finger carried by said cylindrical member at the side ofsaid slide-block opposite from said bearing, said thread-engaging fingerprojecting from said cylindrical take-up member in the direction of saidframe extension, and said frame extension being formed with asubstantially planar thread-guiding slot extending transversely of theaxis of said crank mechanism and disposed entirely within the path ofmotion described by said thread-engaging finger.

11. In a lock-stitch sewing machine having a bracketarm, a rotary shaftjournaled in said bracket arm, a needle-bar journaled for endwisereciprocatory motion in said bracket-arm, a crank mechanism carried bysaid shaft, needle-bar driving connections with said crank mechanism,and a take-up actuating crank-pin carried by said crank mechanism, arotary take-up mechanism comprising a single thread-engaging finger, atake-up member supporting said thread-engaging finger, bearing meanscarried by said take-up member and journaled on said crank-pin, acontrol link pivotally supported with respect to said bracket-arm on anaxis disposed within the path of motion described by said crank-pin,means slidably connecting said control link with said take-up member toprovide a non-circular path of motion of said threadengaging finger, aplate having a periphery shaped to coincide substantially with thenon-circular path of motion of said thread-engaging finger, and meansrigidly supporting said plate from said bracket-arm in a positioncompletely within the path of motion of said threadengaging finger.

12. A rotary take-up mechanism for a sewing machine having a frame, ashaft journaled for rotation in said frame, and a crank mechanismincluding a crank-pin carried for rotation with said shaft, said take-upmechanism comprising, a frame extension including a take-up supportingmember disposed axially opposite said crank mechanism, a bridge piecefixed to said take-up supporting member and means rigidly securing saidbridge piece to said sewing machine frame, a take-up member disposedbetween said take-up supporting member and said crank mechanism, bearingmeans carried by said take-up member and journaled on said crank pin, athreadengaging finger projecting from said take-up member and disposedto extend about the edge of said take-up supporting member, a blockslidable along said take-up member between said bearing means and saidthreadengaging finger, means pivotally securing said block to saidtake-up supporting member on an axis disposed within the path of motiondescribed by said crank-pin.

13. A rotary take-up mechanism for a sewing machine having a frame, ashaft journaled for rotation in said frame, and a crank-pin carried forrotation with said shaft, comprising a frame extension secured to saidframe and disposed axially opposite said shaft, a take-up lever disposedbetween said frame extension and said crank pin, a bearing carried atone end extremity of said lever and journaled on said crank-pin, athread-engaging finger projecting from the opposite extremity of saidtake-up lever in the direction of said frame extension, and meansconfining said thread-engaging finger for motion in a non-circular pathcomprising an anchor link, means pivoting said anchor link to saidtake-up lever means pivoting said anchor link to said frame extension onan axis disposed within the path of motion described by said crank-pin.

14. A rotary take-up mechanism for a sewing machine having a frame, ashaft journaled for rotation in said frame, and a crank mechanismincluding a crank-pin carried for rotation with said shaft, said take-upmechanism comprising a frame extension including a take-up supportingmember disposed axially opposite said crank mechanism, a bridge piecefixed to said take-up supporting member, and means rigidly securing saidbridge piece to said sewing machine frame, a take-up lever disposedbetween said take-up supporting member and said crank mechanism, bearingmeans carried by said take-up lever and journaled on said crank-pin, ananchor link pivoted to said take-up lever, means pivotally securing saidanchor link to said take-up supporting member on an axis disposed withinthe path of motion described by said crankpin, and a thread-engagingfinger projecting from said take-up lever, said thread-engaging fingerbeing disposed to extend about the edge of said take-up supportingmember.

15. In a sewing machine having a frame, a shaft journaled in said frame,and a crank mechanism including a take-up actuating crank-pin carried bysaid shaft, a rotary take-up mechanism comprising a plate rigidlysupported on said frame, said plate having an outer face and an innerface disposed axially opposite said crank mechanism, a take-up leverdisposed between the inner face of said plate and said crank mechanism,an operative connection between said take-up lever and said take-upactuating crank-pin, a single thread-engaging finger projecting fromsaid take-up lever and extending about the edge of said plate, an anchorlink pivoted to said take-up lever, means pivoting said anchor link tothe inner face of said plate on an axis disposed within the path ofmotion described by said crank-pin, and a guard member supported on saidframe in spaced relation to the outer face of said plate to definetherebetween a slot adapted to confine a thread loop within the path ofmotion of said threadengaging finger.

References Cited in the file of this patent UNITED STATES PATENTS196,210 Follett Oct. 16, 1877 2,628,583 Rubel Feb. 17, 1953 FOREIGNPATENTS 3,156 Great Britain 1906

